13232 + Interview Questions in Physics Page 31 InterviewSolution

1501.	A stone weighing 1 kg is dropped from rest from a height of 4 metres above the ground. When it has free-fallen 1 metre its total energy with respect to the ground is
Answer» A stone weighing 1 kg is dropped from rest from a height of 4 metres above the ground. When it has free-fallen 1 metre its total energy with respect to the ground is

Discussion

1502.	A ball weighing 4kg and of density 4000kg/m^3 is completely immersed in water of density 1000kg/m^3. Find the force of buoyancy on it. (Take, g=10m/s^2)
Answer» A ball weighing 4kg and of density 4000kg/m^3 is completely immersed in water of density 1000kg/m^3. Find the force of buoyancy on it. (Take, g=10m/s^2)

Discussion

1503.	Magnifying power for relaxed eye in case of telescope is 9 and length of telescope is 40 cm, then find focal length of eyepiece.
Answer» Magnifying power for relaxed eye in case of telescope is 9 and length of telescope is $40 c m$ , then find focal length of eyepiece.

Discussion

1504.	Why do black holes emit light
Answer» Why do black holes emit light

Discussion

1505.	38.a block of mass m is pulled along with a horizantal surface by ahorizantal rope of mass 1Kg. a force of 15N is applied at free ends of rope the force exerted by block on rope is 13.5N the mass m of block is
Answer» 38.a block of mass m is pulled along with a horizantal surface by ahorizantal rope of mass 1Kg. a force of 15N is applied at free ends of rope the force exerted by block on rope is 13.5N the mass m of block is

Discussion

1506.	A source of wave produces 40 crests and 40 troughs in 0.4 sec. Find the frequency of the wave.
Answer» A source of wave produces 40 crests and 40 troughs in 0.4 sec. Find the frequency of the wave.

Discussion

1507.	Write the density of water at 4∘C in S.I. unit.
Answer» Write the density of water at $4^{\circ} C$ in S.I. unit.

Discussion

1508.	A hollow cylinder of length 3 m has inner and outer diameters of 4 mm and 8 mm respectively. The resistance of the cylinder is (specific resistance of the material =2.2×10−8 Ωm)
Answer» A hollow cylinder of length $3 m$ has inner and outer diameters of $4 mm$ and $8 mm$ respectively. The resistance of the cylinder is (specific resistance of the material $= 2.2 \times 10^{- 8} Ω m)$

Discussion

1509.	When a ball is thrown vertically upwards, it goes through a distance of 19.6 m. find the initial velocity of the ball and the time taken by it to rise to the highest point. (Acceleration due to gravity, g = 9.8 m/s2)
Answer» When a ball is thrown vertically upwards, it goes through a distance of 19.6 m. find the initial velocity of the ball and the time taken by it to rise to the highest point. (Acceleration due to gravity, g = 9.8 m/s²)

Discussion

1510.	In rolling motion on inclined plane, how to find acceleration, frictional force and velocity in a rough surface.
Answer» In rolling motion on inclined plane, how to find acceleration, frictional force and velocity in a rough surface.

Discussion

1511.	The importance of Newton's first law of motion is that:
Answer» The importance of Newton's first law of motion is that:

Discussion

1512.	A pebble is dropped into a well of depth h . The splash is here after time t .if c is the velocity of sound. Then what will be t
Answer» A pebble is dropped into a well of depth h . The splash is here after time t .if c is the velocity of sound. Then what will be t

Discussion

1513.	For hydrogen Oxygen fuel cell, the reaction is 2H2(g) + O2(g) --------> 2H2O(l) Standard energy of formation of H2O = -237.2 kJ/mol. Hence standard EMF of fuel cell is n nt(1) +1.23 V n nt(2) -2.46 V n nt(3) -1.23 V n nt(4) +2.46 V
Answer» For hydrogen Oxygen fuel cell, the reaction is 2H2(g) + O2(g) --------> 2H2O(l) Standard energy of formation of H2O = -237.2 kJ/mol. Hence standard EMF of fuel cell is n nt(1) +1.23 V n nt(2) -2.46 V n nt(3) -1.23 V n nt(4) +2.46 V

Discussion

1514.	Two identical copper spheres with uniform density each of radius R are in contact with each other. If the gravitational attraction between them is F, then
Answer» Two identical copper spheres with uniform density each of radius $R$ are in contact with each other. If the gravitational attraction between them is $F$ , then

Discussion

1515.	A ball is thrown from the top of a tower in vertically upward direction. Velocity at a point h meter below the point of projection is twice of the velocity at a point h meter above the point of projection. Find the maximum height reached by the ball above the top of tower.
Answer» A ball is thrown from the top of a tower in vertically upward direction. Velocity at a point h meter below the point of projection is twice of the velocity at a point h meter above the point of projection. Find the maximum height reached by the ball above the top of tower.

Discussion

1516.	Acceleration of a body varies with displacement according to law a=2x given velocity is zero at x=1 velocity at x =5 is
Answer» Acceleration of a body varies with displacement according to law a=2x given velocity is zero at x=1 velocity at x =5 is

Discussion

1517.	43. A ball A is thrown vertically upward with speed u. At the same time another ball B is released from a height h vertically above the point of projection of A. At any time instant, what is the magnitude of relative velocity of A wrt B?
Answer» 43. A ball A is thrown vertically upward with speed u. At the same time another ball B is released from a height h vertically above the point of projection of A. At any time instant, what is the magnitude of relative velocity of A wrt B?

Discussion

1518.	For what value of angle of incidence a ray incident on a glass plate (μ=1.5) will the reflected ray and the refracted ray be perpendicular to each other?
Answer» For what value of angle of incidence a ray incident on a glass plate $(μ = 1.5)$ will the reflected ray and the refracted ray be perpendicular to each other?

Discussion

1519.	Question 26Sudha finds out that the sharp image of the window pane of her science laboratory is formed at a distance of 15 cm from the lens. She now tries to focus the building visible to her outside the window instead of the window pane without disturbing the lens. In which direction will she move the screen to obtain a sharp image of the building? What is the approximate focal length of this lens?
Answer» Question 26 Sudha finds out that the sharp image of the window pane of her science laboratory is formed at a distance of 15 cm from the lens. She now tries to focus the building visible to her outside the window instead of the window pane without disturbing the lens. In which direction will she move the screen to obtain a sharp image of the building? What is the approximate focal length of this lens?

Discussion

1520.	which factor will have a greater effect on a kinetic enerny of an object doubling its mass or doubling its velocitt
Answer» which factor will have a greater effect on a kinetic enerny of an object doubling its mass or doubling its velocitt

Discussion

1521.	Rahul and Rohan are climbing two different hills of the same height but different inclinations. Rahul's hill is making less angle with horizontal than that of Rohit's. Who is doing more work in climbing to the top? (Assume they have equal mass)
Answer» Rahul and Rohan are climbing two different hills of the same height but different inclinations. Rahul's hill is making less angle with horizontal than that of Rohit's. Who is doing more work in climbing to the top? (Assume they have equal mass)

Discussion

1522.	A car of mass 1200 kg is moving along a straight line with a uniform velocity of 90 kmh. Its velocity is slowed down to 18 kmh−1 in 4 s by an unbalanced external force. Calculate the change in momentum and the magnitude of the force required.
Answer» A car of mass 1200 kg is moving along a straight line with a uniform velocity of 90 $\frac{k m}{h}$ . Its velocity is slowed down to 18 ${k m h}^{- 1}$ in 4 s by an unbalanced external force. Calculate the change in momentum and the magnitude of the force required.

Discussion

1523.	What is momentum conservation
Answer» What is momentum conservation

Discussion

1524.	charges q, -q and q coulomb are placed at the points (-i+j+k), (i-j+k), and (i+j-k) respectively . the x-component of electric field at the origin will be
Answer» charges q, -q and q coulomb are placed at the points (-i+j+k), (i-j+k), and (i+j-k) respectively . the x-component of electric field at the origin will be

Discussion

1525.	ntTwo blocks A and B of mass mA and mB respectively ate kept in contact on a frictionless table.The experimental pushes the block A from behind so that the blocks accelerate.If the block A exerts a force F on the block B,what is the force exerted by the experimental?n
Answer» ntTwo blocks A and B of mass mA and mB respectively ate kept in contact on a frictionless table.The experimental pushes the block A from behind so that the blocks accelerate.If the block A exerts a force F on the block B,what is the force exerted by the experimental?n

Discussion

1526.	ntWhich of the following is the most prescise device for measuring length ?n nt(a) a vernier callipers with 20 divisions on the sliding scalen nt(b) a screw gauge of pitch 1 mm and 100 divisions on the circular scalen nt(c) an optimal instrument that can measure length to within a wavelength of lightn ntAlso explain the reason .n
Answer» ntWhich of the following is the most prescise device for measuring length ?n nt(a) a vernier callipers with 20 divisions on the sliding scalen nt(b) a screw gauge of pitch 1 mm and 100 divisions on the circular scalen nt(c) an optimal instrument that can measure length to within a wavelength of lightn ntAlso explain the reason .n

Discussion

1527.	An electron released on the axis of a positively charged ring at a large distance from the centre will(1) Not move(2) Do oscillatory motion(3) Do SHM(4) Do non-periodic motion
Answer» An electron released on the axis of a positively charged ring at a large distance from the centre will (1) Not move (2) Do oscillatory motion (3) Do SHM (4) Do non-periodic motion

1527.

An electron released on the axis of a positively charged ring at a large distance from the centre will(1) Not move(2) Do oscillatory motion(3) Do SHM(4) Do non-periodic motion

Answer»

An electron released on the axis of a positively charged ring at a large distance from the centre will

(1) Not move

(2) Do oscillatory motion

(3) Do SHM

(4) Do non-periodic motion

Discussion

1528.	वृक्षों से पत्तियाँ तथा वनों से ढाँखें किस माह में गिरते हैं? इससे विरहिणी का क्या संबंध है?
Answer» वृक्षों से पत्तियाँ तथा वनों से ढाँखें किस माह में गिरते हैं? इससे विरहिणी का क्या संबंध है?

Discussion

1529.	18. Aretarding force F= -2v is acting on a body of mass 10 gm. Find out time taken for its velocity to reduce to 37%of its initial value if initial velocity is 1m/s?
Answer» 18. Aretarding force F= -2v is acting on a body of mass 10 gm. Find out time taken for its velocity to reduce to 37%of its initial value if initial velocity is 1m/s?

Discussion

1530.	35.The position of a particle along x axis at time t is given by x=1+t-t². The distance travelled by the particle in first 2 seconds is?
Answer» 35.The position of a particle along x axis at time t is given by x=1+t-t². The distance travelled by the particle in first 2 seconds is?

Discussion

1531.	In which sound will travel fast :(1) Hot water(2) Cold water
Answer» In which sound will travel fast : (1) Hot water (2) Cold water

Discussion

1532.	39.There are 13 equidistant benches in a hall. If a magician releases laughing gas (N2O) from the front and tear gas molar mass 76g/mol from rear simultaneously. the spectators sitting on which bench will laugh with tears first?
Answer» 39.There are 13 equidistant benches in a hall. If a magician releases laughing gas (N2O) from the front and tear gas molar mass 76g/mol from rear simultaneously. the spectators sitting on which bench will laugh with tears first?

Discussion

1533.	Consider the three charged q, q and -q placed at the vertices of an equilateral triangle. What is the force on each charge?
Answer» Consider the three charged q, q and -q placed at the vertices of an equilateral triangle. What is the force on each charge?

Discussion

1534.	Capacitor of capacitance 20 HF is charged to apotential of 500 V, connected in parallel withanother uncharged capacitor of capacitarnce30 uF. The energy loss in redistribution ofcharge isE(1) 2.5J(2) 1 J(3) 0J(4)1.5 J
Answer» Capacitor of capacitance 20 HF is charged to apotential of 500 V, connected in parallel withanother uncharged capacitor of capacitarnce30 uF. The energy loss in redistribution ofcharge isE(1) 2.5J(2) 1 J(3) 0J(4)1.5 J

Discussion

1535.	What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis?
Answer» What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis?

Discussion

1536.	___ ear plays an important role in amplifying the vibrations received on the tympanum membrane.
Answer» ___ ear plays an important role in amplifying the vibrations received on the tympanum membrane.

Discussion

1537.	A skydiver who weighs 60 kg is falling down at a certain speed. He covers 40 m in 2 seconds. The rate of doing work by the skydiver is [Take g=10 m/s2]
Answer» A skydiver who weighs 60 kg is falling down at a certain speed. He covers 40 m in 2 seconds. The rate of doing work by the skydiver is [Take $g = 10 m / s^{2}$ ]

Discussion

1538.	76.What is tesla coil ?
Answer» 76.What is tesla coil ?

Discussion

1539.	An object falls freely from tower and cover 55m in last second.Find height of tower
Answer» An object falls freely from tower and cover 55m in last second.Find height of tower

Discussion

1540.	Neha dropped a stone into a very deep well. She heard the sound only after 6.53 seconds after she dropped the stone. Find the depth of the river if the acceleration due to gravity=10m/s² and the velocity of the sound is 340m/s
Answer» Neha dropped a stone into a very deep well. She heard the sound only after 6.53 seconds after she dropped the stone. Find the depth of the river if the acceleration due to gravity=10m/s² and the velocity of the sound is 340m/s

Discussion

1541.	1. What is the formula for average acceleration of a body revolving in a circular path with constant speed v and radius r?
Answer» 1. What is the formula for average acceleration of a body revolving in a circular path with constant speed v and radius r?

Discussion

1542.	Explain why an iron needle sinks in water, but a ship made of iron floats on water.
Answer» Explain why an iron needle sinks in water, but a ship made of iron floats on water.

Discussion

1543.	The volume of 100g of a substance is 20cm3. If the density of water is 1 gcm−3, the substance will sink?
Answer» The volume of 100g of a substance is $20 c m^{3}$ . If the density of water is 1 $g c m^{- 3}$ , the substance will sink?

Discussion

1544.	Question 2 (ii) State whether the following statement is true or false. Artificial magnets were discovered in Greece.
Answer» Question 2 (ii) State whether the following statement is true or false. Artificial magnets were discovered in Greece.

1544.

Question 2 (ii) State whether the following statement is true or false. Artificial magnets were discovered in Greece.

Answer»

Question 2 (ii)

State whether the following statement is true or false.

Artificial magnets were discovered in Greece.

Discussion

1545.	Question 20 What is momentum? Write its SI unit. Interpret force in terms of momentum. Represent the following graphically (a) momentum versus velocity when mass is fixed. (b) momentum versus mass when velocity is constant
Answer» Question 20 What is momentum? Write its SI unit. Interpret force in terms of momentum. Represent the following graphically (a) momentum versus velocity when mass is fixed. (b) momentum versus mass when velocity is constant

Discussion

1546.	56.The figure shows the p-V plot of an ideal gas taken through a cycle ABCDA.The part ABC is semi circle and CDA is half of an ellipse.Then, a)the process during the path AB is isothermal b)heat flows out of the gas during the path BCD c)work done during the path ABC is zero d)positive work is done by the gas in the cycle ABCDA
Answer» 56.The figure shows the p-V plot of an ideal gas taken through a cycle ABCDA.The part ABC is semi circle and CDA is half of an ellipse.Then, a)the process during the path AB is isothermal b)heat flows out of the gas during the path BCD c)work done during the path ABC is zero d)positive work is done by the gas in the cycle ABCDA

Discussion

1547.	A particle is projected from level ground with velocity 20 m/s at an angle of 53^° above the horizontal. At the ins†an t its velocity is perpendicular to the velocity of projection, its height from the ground will be \lbrack g = 10 m/s2\rbrack
Answer» A particle is projected from level ground with velocity 20 m/s at an angle of 53^° above the horizontal. At the ins†an t its velocity is perpendicular to the velocity of projection, its height from the ground will be \lbrack g = 10 m/s2\rbrack

Discussion

1548.	What is motion defination in physics language with physics word used meaning.
Answer» What is motion defination in physics language with physics word used meaning.

Discussion

1549.	In the above food web, if wild cat becomes extinct, then which animal’s population would increase?
Answer» In the above food web, if wild cat becomes extinct, then which animal’s population would increase?

1549.

In the above food web, if wild cat becomes extinct, then which animal’s population would increase?

Answer»

In the above food web, if wild cat becomes extinct, then which animal’s population would increase?

Discussion

1550.	A sinusoidal wave propagates along a string in figure (a) and (b). 'y' represents displacement of particle from the mean position. 'x' & 't' have usual meanings. Find:1. Wavelength, frequency and speed of the wave2. Maximum velocity and maximum acceleration of the particles
Answer» A sinusoidal wave propagates along a string in figure (a) and (b). 'y' represents displacement of particle from the mean position. 'x' & 't' have usual meanings. Find: 1. Wavelength, frequency and speed of the wave 2. Maximum velocity and maximum acceleration of the particles

1550.

A sinusoidal wave propagates along a string in figure (a) and (b). 'y' represents displacement of particle from the mean position. 'x' & 't' have usual meanings. Find:1. Wavelength, frequency and speed of the wave2. Maximum velocity and maximum acceleration of the particles

Answer»

A sinusoidal wave propagates along a string in figure (a) and (b). 'y' represents displacement of particle from the mean position. 'x' & 't' have usual meanings. Find:

1. Wavelength, frequency and speed of the wave

2. Maximum velocity and maximum acceleration of the particles

Discussion

Explore topic-wise InterviewSolutions in .

A stone weighing 1 kg is dropped from rest from a height of 4 metres above the ground. When it has free-fallen 1 metre its total energy with respect to the ground is

A ball weighing 4kg and of density 4000kg/m^3 is completely immersed in water of density 1000kg/m^3. Find the force of buoyancy on it. (Take, g=10m/s^2)

Magnifying power for relaxed eye in case of telescope is 9 and length of telescope is 40 cm, then find focal length of eyepiece.

Why do black holes emit light

38.a block of mass m is pulled along with a horizantal surface by ahorizantal rope of mass 1Kg. a force of 15N is applied at free ends of rope the force exerted by block on rope is 13.5N the mass m of block is

A source of wave produces 40 crests and 40 troughs in 0.4 sec. Find the frequency of the wave.

Write the density of water at 4∘C in S.I. unit.

A hollow cylinder of length 3 m has inner and outer diameters of 4 mm and 8 mm respectively. The resistance of the cylinder is (specific resistance of the material =2.2×10−8 Ωm)

When a ball is thrown vertically upwards, it goes through a distance of 19.6 m. find the initial velocity of the ball and the time taken by it to rise to the highest point. (Acceleration due to gravity, g = 9.8 m/s2​)

In rolling motion on inclined plane, how to find acceleration, frictional force and velocity in a rough surface.

The importance of Newton's first law of motion is that:

A pebble is dropped into a well of depth h . The splash is here after time t .if c is the velocity of sound. Then what will be t

For hydrogen Oxygen fuel cell, the reaction is 2H2(g) + O2(g) --------> 2H2O(l) Standard energy of formation of H2O = -237.2 kJ/mol. Hence standard EMF of fuel cell is n nt(1) +1.23 V n nt(2) -2.46 V n nt(3) -1.23 V n nt(4) +2.46 V

Two identical copper spheres with uniform density each of radius R are in contact with each other. If the gravitational attraction between them is F, then

A ball is thrown from the top of a tower in vertically upward direction. Velocity at a point h meter below the point of projection is twice of the velocity at a point h meter above the point of projection. Find the maximum height reached by the ball above the top of tower.

Acceleration of a body varies with displacement according to law a=2x given velocity is zero at x=1 velocity at x =5 is

43. A ball A is thrown vertically upward with speed u. At the same time another ball B is released from a height h vertically above the point of projection of A. At any time instant, what is the magnitude of relative velocity of A wrt B?

For what value of angle of incidence a ray incident on a glass plate (μ=1.5) will the reflected ray and the refracted ray be perpendicular to each other?

which factor will have a greater effect on a kinetic enerny of an object doubling its mass or doubling its velocitt

Rahul and Rohan are climbing two different hills of the same height but different inclinations. Rahul's hill is making less angle with horizontal than that of Rohit's. Who is doing more work in climbing to the top? (Assume they have equal mass)

A car of mass 1200 kg is moving along a straight line with a uniform velocity of 90 kmh. Its velocity is slowed down to 18 kmh−1​ in 4 s by an unbalanced external force. Calculate the change in momentum and the magnitude of the force required.

What is momentum conservation

charges q, -q and q coulomb are placed at the points (-i+j+k), (i-j+k), and (i+j-k) respectively . the x-component of electric field at the origin will be

ntTwo blocks A and B of mass mA and mB respectively ate kept in contact on a frictionless table.The experimental pushes the block A from behind so that the blocks accelerate.If the block A exerts a force F on the block B,what is the force exerted by the experimental?n

An electron released on the axis of a positively charged ring at a large distance from the centre will(1) Not move(2) Do oscillatory motion(3) Do SHM(4) Do non-periodic motion

वृक्षों से पत्तियाँ तथा वनों से ढाँखें किस माह में गिरते हैं? इससे विरहिणी का क्या संबंध है?

18. Aretarding force F= -2v is acting on a body of mass 10 gm. Find out time taken for its velocity to reduce to 37%of its initial value if initial velocity is 1m/s?

35.The position of a particle along x axis at time t is given by x=1+t-t². The distance travelled by the particle in first 2 seconds is?

In which sound will travel fast :(1) Hot water(2) Cold water

39.There are 13 equidistant benches in a hall. If a magician releases laughing gas (N2O) from the front and tear gas molar mass 76g/mol from rear simultaneously. the spectators sitting on which bench will laugh with tears first?

Consider the three charged q, q and -q placed at the vertices of an equilateral triangle. What is the force on each charge?

Capacitor of capacitance 20 HF is charged to apotential of 500 V, connected in parallel withanother uncharged capacitor of capacitarnce30 uF. The energy loss in redistribution ofcharge isE(1) 2.5J(2) 1 J(3) 0J(4)1.5 J

What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis?

___ ear plays an important role in amplifying the vibrations received on the tympanum membrane.

A skydiver who weighs 60 kg is falling down at a certain speed. He covers 40 m in 2 seconds. The rate of doing work by the skydiver is [Take g=10 m/s2]

76.What is tesla coil ?

An object falls freely from tower and cover 55m in last second.Find height of tower

Neha dropped a stone into a very deep well. She heard the sound only after 6.53 seconds after she dropped the stone. Find the depth of the river if the acceleration due to gravity=10m/s² and the velocity of the sound is 340m/s ​​​​​

1. What is the formula for average acceleration of a body revolving in a circular path with constant speed v and radius r?

Explain why an iron needle sinks in water, but a ship made of iron floats on water.

The volume of 100g of a substance is 20cm3. If the density of water is 1 gcm−3, the substance will sink?

Question 2 (ii) State whether the following statement is true or false. Artificial magnets were discovered in Greece.

Question 20 What is momentum? Write its SI unit. Interpret force in terms of momentum. Represent the following graphically (a) momentum versus velocity when mass is fixed. (b) momentum versus mass when velocity is constant

A particle is projected from level ground with velocity 20 m/s at an angle of 53^° above the horizontal. At the ins†an t its velocity is perpendicular to the velocity of projection, its height from the ground will be \lbrack g = 10 m/s2\rbrack

What is motion defination in physics language with physics word used meaning.

In the above food web, if wild cat becomes extinct, then which animal’s population would increase?

A sinusoidal wave propagates along a string in figure (a) and (b). 'y' represents displacement of particle from the mean position. 'x' &amp; 't' have usual meanings. Find:1. Wavelength, frequency and speed of the wave2. Maximum velocity and maximum acceleration of the particles

When a ball is thrown vertically upwards, it goes through a distance of 19.6 m. find the initial velocity of the ball and the time taken by it to rise to the highest point. (Acceleration due to gravity, g = 9.8 m/s2)

A car of mass 1200 kg is moving along a straight line with a uniform velocity of 90 kmh. Its velocity is slowed down to 18 kmh−1 in 4 s by an unbalanced external force. Calculate the change in momentum and the magnitude of the force required.

Neha dropped a stone into a very deep well. She heard the sound only after 6.53 seconds after she dropped the stone. Find the depth of the river if the acceleration due to gravity=10m/s² and the velocity of the sound is 340m/s

A sinusoidal wave propagates along a string in figure (a) and (b). 'y' represents displacement of particle from the mean position. 'x' & 't' have usual meanings. Find:1. Wavelength, frequency and speed of the wave2. Maximum velocity and maximum acceleration of the particles